This invention relates to a dust control system, e.g., a system for controlling dust generated by the operation of a mining machine, and more particularly to such a system for controlling dust in underground coal mining operations.
The invention is especially concerned with the problem of removing dust from the air in a mine in the vicinity of equipment which, in use in the mine, generates dust. It is particularly concerned, for example, with the removal of dust from the air in the vicinity of the working face of a mine, and particularly a coal mine, generated by a mining machine such as a machine of the type referred to as a continuous miner, as a result of the cutter of the machine cutting into the working face. The dust includes particles of various sizes; this invention is particularly concerned with the removal from the air of what is generally referred to as "respirable dust", for compliance with government regulations relating to control of respirable dust, and in particular for compliance with the Federal 1969 Health and Safety Act which requires exposure to respirable dust levels to be below 2 milligrams per cubic meter for an eight hour work shift. It will be understood that respirable dust is fine-particle dust, generally comprising particles less than 5 microns in size, which may accumulate in a miner's lungs and cause pneumoconiosis. The problem of controlling dust, and especially respirable dust, is compounded when it is desired to use what is referred to as a blowing face mine ventilation system, which is a system in which air for ventilation at the working face in a mine entry is blown at relatively high velocity toward the working face between a side wall of the entry and a curtain extending generally parallel to said side wall. The blowing face system of ventilation is generally effective for ventilation but may cause dust problems, in contrast to the exhaust type of mine face ventilation (in which air is exhausted from the entry after delivery to the face at relatively low velocity) which is not as good for ventilation as the blowing face system, but which does not cause as much of a dust problem as the blowing face system.